Pituitary - Summary Notes

·




·
sits within
Endocrinology

regulated by Hypothalamus.
Sella Turcica.
Pituitary
Anterior P.

via
Stimulated
bloodstream hormones. HP AXIS
Posterior P. Stimulated

directly by neurones.
Infundibulum
Hypothalamus: Dopamine
-




GH
releasing (GHRH), Somatostatin
-




Gonadotropin releasing (GnRH)
-




-Thyrotropin releasing(TRA)
corticotropin releasing (CRH)
-




Anterior
Pituitary: -
ACTH
-

TSH
-


FSH/LH
-

GH
Prolactin
-




Posterior
Pituitary:
-
Antidiuretic (ADH)
oxytocin
-




CORTISOL SECRETION
GHEATHWAY
A. Hormones
·ACTH:stimulated by CRH.


·
Promotes Cortisol Secretion from adrenals.
low
levels in
Very sleep, high
·
in
morning.
ACTH Adrenal
hyperplasia,
· =




ACTH Adrenal GH PULSATILE
SECRETION
Atrophy.
=




o
TSH: stimulated by TRH.


Promotes Ts/Tyrelease from Thyroid.
·




·


Negative feedback from Ts/Fr.


·FSH/CH:stimulated by GnRH.


Promote sex hormone release from gonads, inhibited
by
·




to induce other
secondary effects. Prolactin:
Dopamine.
·
going on




·GH: stimulated by GHRH, inhibited by Somatostatin. ·Induces lactation,

Suppresses GnRH.

Regulates many growth/metabolic functions. during
abundant
· ·
more

·
Released in zulsatile pattern higher in sleep.
-




pregnancy/breastfeeding.
·
Liver produces IGF-1 in response, which modulates GHeffects.

IGF-1levels can be used to screen for GH oversecretion.
·
stimulated by hypoglycaemia, sleep, exercise.

Suppressed by hyperglycaemia.